I have a problem when hose is connected to my van the water presssure inside van is very low . If. I have just replaced the one way valve inside van {other side of hose bringing water into van}, i turn water pump on pressure is great , to me appears to be ablockage on main waterpipe past one way valve. ANY HELP /IDEAS please.
Symptomatic of the vans Pressure Reducing Valve (PRV) becoming stuck. Many van spare parts businesses sell them or hardware or plumbing supplies, but of course one needs to know which type etc. Or if you can remove the PRV and have the tools and strength, the PRV can be dismantled and lubricated. Or without any removal, hit the PRV with a hammer which may loosen its internal workings.
